Know Your Environment. Protect Your Health.

Haloacetic acids (HAA5)

Gonzales County Water Supply Corporation

Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of five haloacetic acids regulated by federal standards includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. Read More.

Haloacetic acids are harmful during pregnancy and may increase the risk of cancer. Haloacetic acids are� genotoxic, which means that they induce mutations and DNA damage. Multiple studies by the National Toxicology Program have demonstrated the cancer-causing properties of individual haloacetic acids in laboratory animals. The Department of Health and Human Services is currently considering listing di- or tri-haloacetic acids for possible inclusion in its comprehensive Report on Carcinogens.

Click here to read more about disinfection byproducts.

 

47

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND80ND
20192.85 ppb81ND - 22.8 ppb
2020ND80ND
2021ND80ND
2022ND70ND
2023ND80ND

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.1 ppb

The EWG Health Guideline of 0.1 ppb for the group of five haloacetic acids, or HAA5, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level. This health guideline protects against cancer.

EPA Maximum Contaminant
Level (MCL): 60 ppb

The legal limit for the group of five haloacetic acids (HAA5), established in 1998, was based on the need for residual disinfectant levels in water served to customers and the cost of treatment. This limit does not fully protect against the risk of cancer and harm to the developing fetus due to exposure to haloacetic acids.

ppb = parts per billion

All test results

Date Lab ID Result
2018-02-08AE12981ND
2018-02-08AE12980ND
2018-05-03AE25055ND
2018-05-03AE25012ND
2018-08-16AE37317ND
2018-08-16AE37318ND
2018-12-12AE48632ND
2018-12-12AE48633ND
2019-03-05AE57116ND
2019-03-05AE5711722.8 ppb
2019-04-02AE60853ND
2019-04-02AE60858ND
2019-07-12AE74352ND
2019-07-12AE74353ND
2019-10-14AE86437ND
2019-10-14AE86439ND
2020-01-21AE94302ND
2020-01-21AE94304ND
2020-04-13AF06460ND
2020-04-13AF06461ND
2020-08-24AF24854ND
2020-08-24AF24855ND
2020-11-13AF34876ND
2020-11-13AF34874ND
2021-01-13AF39103ND
2021-01-13AF39104ND
2021-04-01AF48828ND
2021-04-01AF48829ND
2021-08-18AF66871ND
2021-08-18AF66873ND
2021-10-05AF72258ND
2021-10-05AF72260ND
2022-02-09AF83956ND
2022-02-09AF83957ND
2022-04-20AF93871ND
2022-04-20AF93870ND
2022-09-30AG15663ND
2022-09-30AG15664ND
2022-12-09AG21487ND
2023-03-15AG33167ND
2023-03-15AG33168ND
2023-06-21AG45238ND
2023-06-21AG45239ND
2023-09-11AG55537ND
2023-09-11AG55539ND
2023-11-28AG64588ND
2023-11-28AG64590ND